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MX-5 Miata Mazdaspeed 2004-05 (BP-ZET turbo, no VVT) → MaxxECU MaxxECU RACE REV9+ (auto)

MX-5 Miata Mazdaspeed 2004-05 (BP-ZET turbo, no VVT) — MaxxECU — MaxxECU RACE
⚠ NOT CHECKED. Don't build from this.
Drawn by Michael Gnankou · Rev 0 · draft · 2026-10-11

Before you start

Not confident with automotive wiring? Have a professional harness builder or tuner do it, or check your work before first power-up. A wiring mistake can damage the ECU, the engine or the car, or start a fire.

Statusdraft · not yet verified: nobody has reported building and running this harness
Open errors3: read the Findings page before cutting any wire
Size of the job4 wires · 3 connectors · 0 part lines
ToolsCrimp and extraction tools for each terminal family (see Connectors) · wire strippers · multimeter · heat gun + heat-shrink
Order of work1. Check every part against the parts list. 2. Cut and label every wire (labels: Export → Wire labels). 3. Crimp and pin connector by connector, ticking the build checklist. 4. Run the bench test with nothing plugged in and the battery disconnected. 5. Only then connect the ECU and power up.

Build checklist

Tick each box as you go. Continuity: meter from end to end, expect under 1 Ω.

WireFromToGaugeColourCutLabelCrimp ACrimp BPin APin BContinuity
W1OEM-4-DMAXXECURACE-C2-G10.5☐☐☐☐☐☐☐
W2OEM-4-EMAXXECURACE-C2-G20.5☐☐☐☐☐☐☐
W3OEM-4-AEMAXXECURACE-C1-J30.5☐☐☐☐☐☐☐
W4OEM-4-RMAXXECURACE-C1-J10.5☐☐☐☐☐☐☐

Bench test (before first power-up)

Battery disconnected, ECU and every sensor unplugged. Meter on resistance. Each pair below must read open (OL): a reading means a pinched wire, a stray strand or a mis-pinned cavity. Then check continuity of every wire (last column of the build checklist).

#Probe AProbe BExpectWhyReading
No supply/ground nets found to cross-check.

If any reading doesn't match, stop and get help before powering up.

Revisions

RevLabelByDate
No revisions yet.

Schematic

MAXXECURACE-C1MAXXECURACE-C2OEM-2OEM-3OEM-4

Connectors

MAXXECURACE-C1

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
A1GPO 5————————
A2IGN 1————————
A3IGN 2————————
A4GPO 8/TACHO————————
B1GPO 6————————
B2IGN 3————————
B3IGN 4————————
B4GPO 1————————
C1GPO 7————————
C2IGN 5————————
C3IGN 6————————
C4GPO 2————————
D1WBO2 Heater-————————
D2IGN 7————————
D3IGN 8————————
D4GPO 3————————
E1CAN H————————
E2CAN L————————
E3GND Shield————————
E4GPO 4————————
F1CLT————————
F2IAT————————
F3WBO2 VREF————————
F4WBO2 VS————————
G1+5V sensor supply————————
G2TPS/AIN————————
G3WBO2 IP————————
G4WBO2 RCAL————————
H1Sensor GND————————
H2Trigger GND————————
H3TRIGGER————————
H4HOME————————
J1AIN 1 (temperature)—W4—0.5OEM-4-R———
J2AIN 2 (temperature)————————
J3AIN 3 (0-5V)—W3—0.5OEM-4-AE———
J4AIN 4 (0-5V)————————
K1INJ 1————————
K2INJ 2————————
K3DIN/VR 1————————
K4DIN/VR 2————————
L1INJ 8————————
L2INJ 7————————
L3INJ 6————————
L4Engine GND————————
M1INJ 3————————
M2INJ 4————————
M3INJ 5————————
M4+12V ECU power supply————————

MAXXECURACE-C2

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
A1EGT 5+————————
A2EGT 6+————————
A3EGT 7+————————
A4EGT 8+————————
B1EGT 5-————————
B2EGT 6-————————
B3EGT 7-————————
B4EGT 8-————————
C1EGT 1+————————
C2EGT 2+————————
C3EGT 3+————————
C4EGT 4+————————
D1EGT 1-————————
D2EGT 2-————————
D3EGT 3-————————
D4EGT 4-————————
E1KNOCK GND————————
E2Knock 1————————
E3Knock 2————————
E4AIN 6 (0-5V)————————
F1AIN 7 (0-5V)————————
F2AIN 8 (0-5V)————————
F3DIN/VR 4————————
F4DIN/VR 5————————
G1GPO 15 (+12V)—W1—0.5OEM-4-D———
G2GPO 16 (+12V)—W2—0.5OEM-4-E———
G3AIN 5 (0-5V)————————
G4ENGINE GROUND————————
H1MOTOR 2+————————
H2MOTOR 1-————————
H3MOTOR 2-————————
H4MOTOR 1+————————

OEM-4

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
ACData link connector (DLC TEN, turbo)————————
AEBARO/MAP sensor (turbo boost pressure)—W3—0.5MAXXECURACE-C1-J3———
DBoost control solenoid (turbo)—W1—0.5MAXXECURACE-C2-G1———
EBoost control solenoid (turbo)—W2—0.5MAXXECURACE-C2-G2———
RIntake air temperature 2 (IAT2, turbo)—W4—0.5MAXXECURACE-C1-J1———

Pin map

OEM pointOEM functionOEM familyTarget pointTarget functionTarget familyWire colourEvidence
OEM-4-ACData link connector (DLC TEN, turbo)serial———BrYsingle_source
OEM-4-AEBARO/MAP sensor (turbo boost pressure)analog_inMAXXECURACE-C1-J3AIN 3 (0-5V)analog_inLYsingle_source
OEM-4-DBoost control solenoid (turbo)high_side_outMAXXECURACE-C2-G1GPO 15 (+12V)high_side_outYsingle_source
OEM-4-EBoost control solenoid (turbo)high_side_outMAXXECURACE-C2-G2GPO 16 (+12V)high_side_outYsingle_source
OEM-4-RIntake air temperature 2 (IAT2, turbo)temp_inMAXXECURACE-C1-J1AIN 1 (temperature)temp_inVYsingle_source

Cut list

WireFromToGauge (mm²)ColourLengthSignalIdent
W1OEM-4-DMAXXECURACE-C2-G10.5no routeBoost control solenoid (turbo)—
W2OEM-4-EMAXXECURACE-C2-G20.5no routeBoost control solenoid (turbo)—
W3OEM-4-AEMAXXECURACE-C1-J30.5no routeBARO/MAP sensor (turbo boost pressure)—
W4OEM-4-RMAXXECURACE-C1-J10.5no routeIntake air temperature 2 (IAT2, turbo)—

Bill of materials

CategoryPart numberManufacturerDescriptionQtyUnit

ECU setup sheet

RoleEngine refEngine signalSensorECU pointECU functionECU classSetup flag
No configured channels.

Findings

Open (4)

SeverityCodeSubjectMessage
errorPHYS_REQUIRED_OPENMAXXECURACE-C1-L4MAXXECURACE-C1-L4 "Engine GND" is required but not wired.
errorPHYS_REQUIRED_OPENMAXXECURACE-C1-M4MAXXECURACE-C1-M4 "+12V ECU power supply" is required but not wired.
errorPHYS_REQUIRED_OPENMAXXECURACE-C2-G4MAXXECURACE-C2-G4 "ENGINE GROUND" is required but not wired.
infoUNMAPPEDOEM1 optional OEM pins are not mapped: OEM-4-AC Data link connector (DLC TEN, turbo)

Accepted (0)

CodeSubjectReasonBy

Notes

Auto-mapped by auto_map() from the library pin data on 2026-10-11. Review every wire against both manuals before building. Open items: - Main-relay feed: no ecu_main_power pin on the stock or the new ECU - MAXXECURACE-C1 L4: Engine GND: required by MaxxECU MaxxECU RACE but no stock pin feeds it; wire by hand - MAXXECURACE-C1 M4: +12V ECU power supply: required by MaxxECU MaxxECU RACE but no stock pin feeds it; wire by hand - MAXXECURACE-C2 G4: ENGINE GROUND: required by MaxxECU MaxxECU RACE but no stock pin feeds it; wire by hand Not wired: - OEM-4 AC: Data link connector (DLC TEN, turbo): no free k_line on MaxxECU MaxxECU RACE

Sources

ReliabilityKindTitleURLArchiveCapturedSHA-256
4oem_manual2005 Mazda MX-5 Miata Engine Performance Control System (PCM terminal voltage reference, BP and BP WITH TC)https://trull.org/alex/pubmirror/www.mellens.net/mazda/Mazda-Miata-2005/engine_control_system.pdf———
4vendor_docAdaptronic eSel039 Select Plugin ECU for Mazda MX5 / Miata NB8B/C (OEM ECU pinout)https://www.miataturbo.net/attachments/ecus-tuning-54/04-msm-ecu-pinout-104032/nb8bc_oem_ecu_pinouts-224948d1602912806———
4vendor_docMaxxECU GEN1 pinout (MINI / STREET / SPORT / V1 / RACE / PRO)http://www.maxxecu.com/webhelp/wirings-maxxecu_pinout.htmlarchive2026-10-052e37b6814690